84 
MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ PaRT I : 
Since the foregoing paragraph was written I have been able to visit 
the manganese-ore deposits at Ramandrug and Kamataru in the Sandur 
Hills, and find this supposed manganite myself. It occurs in drusy 
cavities in the ore-bodies, and may occur in either wad or psilomelane. 
Specimens can be found showing every gradation between the hard 
bronzy-lustred mineral mentioned above, and a shining black mineral 
of exactly the same radiate character, but as soft as pyrolusite, which it 
then undoubtedly is. Of the specimens sent by Mr. Aubert some of the 
harder bronzy-lustred mineral was separated from the associated ores 
and the specific gravity of a piece weighing 2 "19 grammes found to be 
Chemical compo- 4-470. This being only slightly higher than the 
value of this constant for the unaltered manganite, 
which is 4'2-'1:"4, it was thought that analysis would show this piece to 
be nearly fresh manganite. The analysis was undertaken by Mr. C, 
Fawcitt of Shimoga with the following result :- 
Mn02 92-90 
MnO 1-47 
Fe203 and AlaOs (mostly AI2O3) 1-88 
CaO 0-86 
MgO ■ 0-52 
Si02 0-47 
Combined water . , . • . . , . I • 94 
100-04 
From this analysis it will be seen that — in spite of the fact that in 
physical characters the mineral presents considerable differences from, 
pyrolusite, and considerable resemblances to manganite — chemically the 
mineral is not far removed from pyrolusite. It is true that it still retains 
nearly 2 per cent, out of the original 10 per cent, of combined water it 
must have once contained, whilst there is still a small quantity of man- 
ganese protoxide remaining. Hence we arrive at the dilemma that this 
mineral, which was once almost certainly manganite, retains to a consi- 
derable extent the physical characters of manganite, but has been almost 
completely converted into p}Tolusite, as far as chemical composition 
goes. As it would be most inconvenient to call this mineral pjTolusite, 
owing to its different physical appearance. -and inaccurate to call it man- 
■p ^ .J ganite, I propose to refer to it as pseudo-manganite. 
' It must be remembered that the above analysis 
represents nuly one piece of the mineral. It is possible that if several 
